1. Field of the Invention
The present invention relates to a method for preparing impression taking and molding materials by mixing and kneading chemical material powder with a proper quantity of water for dental diagnosis and treatment, and to dental chemical materials used in the method.
2. Description of the Prior Art
The chemical materials include dental alginate impression material (alginic acid salt), dental plaster, dental filling and restoration material known as a trademark "IONODENT" manufactured by Sankin Kogyo Kabushiki Kaisha (a mixture of carboxylic acid polymern and aluminosilicate) and dental cement, the selection and amount of which are determined according to each clinical case.
These materials have a property of being made plastic when mixed with water and become harder with time. Therefore, when it is desired to take patient's tooth impression with use of, for example, the alginate impression material, the quantity of the impression material powder required for the clinical treatment is conventionally measured with a measuring cup, and then the measured material powder and a proper amount of water are mixed and kneaded to a desired state suitable for the impression taking or impression molding. The quantity of the alginate impression material is prescribed to be 21, 14 and 7 grams for 1, 1/2 jaws and 2-3 teeth, respectively, while the powder measuring cup is designed for measurement of the minimum unit, in this case, 7 grams. When an impression of one jaw is to be taken, the cup is used three times to obtain the desired amount of the impression material powder, then the measured material is mixed with a proper quantity of water. The other chemical materials are prepared in the same manner.
As described above, prior to preparation of dental impression taking or molding material, a measuring tool such as the aforementioned cup must have been used to measure the chemical material of the amount necessary for respective clinical treatment. Thus, the conventional preparing method has many problems including the followings:
(1) Measurement of powder is troublesome and time-consuming.
(2) During such measurement, powder tends to fly off in different directions, which leads to an unhygienical examination room and powder loss.
(3) Since such chemical powder is usually stored in a container such as a can or a bag, some powder tends to remain in the bottom of the container as waste powder.
(4) Each measurement is not always accurate, and thus the ratio of mixture of the material to water is frequently inaccurate, which leads to a low impression taking or molding accuracy.
(5) The impression material and measuring tools must be maintained clean. In other words, they tend to be insanitary.